1 algae biofuel b. greg mitchell scripps institution of oceanography university of california, san...

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Algae Biofuel

B. Greg MitchellScripps Institution of OceanographyUniversity of California, San Diego

gmitchell@ucsd.edu

With contributions fromSempra Utilities, Earthrise

LiveFuels, Inc, General AtomicsNeste Oil and The Scripps Research Institute

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Algae very diverse: microscopic to giant kelpEfficient, rapid growth, can double biomass in a dayProduce 50% of oxygen but are less than 1% of all plant biomass Few species have been studied for biofuel potential

Chlorophyceae Dinophyceae Bacillariophyceae

Algae are photosynthetic organisms

CO2 + H2O + Light Energy Biomass

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Ethanol and Biodiesel Feedstocks Must Be Expanded if They are to Contribute Substantially

Reliance on food crops undesirable – and Limiting

Cellulosic ethanol could be part of the solution

Ethanol and biodiesel needs a non-food feedstock

Algae Can Play that Role:

Can be grown on non-arable land in saline water

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Unique Potential of Algae Biodiesel

• Soybean Based Biodiesel will never contribute more than a few percent of the possible US diesel fuel market

• ~20 million acres of algae would supply ALL US transportation fuel– Small fraction of current land use– US currently uses ~970 million

acres for crops & grazing

CropGal/Acre/yrOf Oil

Soybean 48

Peanuts 113

Rapeseed 124

Coconut 287

Palm Oil 635

Algae 15,000

Yield per acre

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ALGAE BIOFUEL – REDUCED GLOBAL WARMING & LOWERED ENVIRONMENTAL IMPACTS

• Algae requires CO2 for growth therefore fuel is carbon neutral

• Possible integration to achieve low-cost CO2 sequestration and nutrient remediation

• Uses all nutrients, minimizing eutrophication• Biodegradable, so minimal issues with accidental spills /leaks • Uses underutilized land, e.g. deserts• Yields >10x those for land plants so much less land is needed• Can grow in salt, or brackish water• Can produce high yields of

– Lipids for biodiesel– starch / polysaccharides for ethanol

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Encouraging Cost Projections Analysis by General Atomics

Costs of Biodiesel from Algae

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500

1000

1500

2000

2500

3000

3500

4000

4500

0 0.5 1 1.5 2 2.5 3

$/gal diesel

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Option Rate Impact GHG Impact Market Readiness/ Issues

Biogas -

Manure, Wastewater, Stillage

Neutral to slight negative based on scale

High Ready Now; Needs scale

Microalgae Neutral to slight negative

High 5 Years; Land requirement; Tech. development

Energy Crops- Switch grass, willow hybrid poplar

TBD Medium to High 5-10 Years; Yields need to improve; land requirement and logistics issues

Biomass Pyrolysis and gasification – Forestry Residue

Negative Medium Needs significant development and scale economies for commercialization

Evaluation of various Biofuel Options Sempra Utilities

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Engineering a Photosynthetic Hydrocarbon MixSteve Mayfield The Scripps Research Institute

Potential to convert light energy directly to fuel molecules

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Vision for a Center of Excellence for algae bio-energy research, development and demonstration

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Earthrise Algae FarmCalipatria, Ca

Salton Sea

Feasibility of algae farming proven

Scale up for biofuel will be a challenge